1. Field of the Invention
The present invention relates, generally, to a method and apparatus for processing, moving and loading materials, articles, apparatus or structures utilizing cooling means or steps. Particularly, the invention relates to a method of cooling and processing an article to facilitate loading into another article, structure or space. Most particularly, the invention relates to a method and apparatus for loading an article such as a medical stent, stent graft or the like (particularly self-expanding stents or other articles) into medical catheters, tubes, carriers, housings and the like.
2. Background Information
The state of the art includes stents, stent grafts and the like, loaders for such articles, and crimpers. Included in known stents are self-expanding type stents. Included in crimpers are crimpers which have means for cooling certain parts of the crimper.
Self-expanding stents are fragile precision articles used in intravasular (including but not limited to cardiac vascular procedures) medical procedures, typically therapeutic procedures. They are comprised of a fine mesh structure with a tubular configuration of a predetermined length. The stent tube has a central lumen which serves as a space for holding the stent. They are typically made of a shape memory material such as NITINOL. Manufactured stents are loaded into a deployment device such as a catheter typically by temporarily reducing the diameter of the stent (for example by crimping or otherwise radially compressing them) to slightly less than that of the deployment catheter lumen, and then inserting the reduced diameter stent into an open end of the deployment catheter lumen (typically the distal end of the deployment catheter). In typical use, the deployment catheter is inserted into and moved through the vasculature by well known percutaneous and fluoroscopic procedures. At the appropriate therapeutic location, a control piece in the catheter is actuated to push the stent out of the distal end. Once the stent is out of the catheter lumen, and no longer constrained by the catheter, the shape memory properties of the stent cause it to expand naturally in the vasculature.
Loading of the stent from the diameter reduction means to the deployment catheter is important and challenging. Known methods of loading self-expanding stents into delivery catheters include “push loading” and “inch-worm loading.” The stent is difficult to handle and move anywhere by virtue of its small size, and flexibility. Longitudinal movement is particularly difficult, especially for long stents. And movement into the small lumen of the catheter is most particularly difficult. Also, loading must take place as the stent seeks to expand at any time and point where it is not radially constrained by the reduction or deployment means.
In summary, the known existing technology is believed to have limitations and shortcomings and a need exists for the present invention.
All US patents and patent applications, and all other published documents mentioned anywhere in this application are incorporated by reference in their entirety.